<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            width: 200px;
            height: 100px;
            border: 1px solid red;
            float: left;
        }
        ul{
            clear: both;
            width: 100px;
            border: 1px solid blue;
        }
    </style>
</head>
<body>
<div>div1</div>
<div>div2</div>
<ul>
    <li>列表</li>
</ul>
</body>
</html>